MAINTAINERS: Update after GEHC spin-off

Update our email addresses, from @ge.com to @gehealthcare.com, after GE
HealthCare was spun-off from GE.

Remove Antti, who no longer works on the project.

Signed-off-by: Ian Ray <ian.ray@gehealthcare.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 32f3ee3..73ee4fe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -455,7 +455,7 @@
 
 ARM MSC SM2S IMX8MP SOM
 M:	Martyn Welch <martyn.welch@collabora.com>
-M:	Ian Ray <ian.ray@ge.com>
+M:	Ian Ray <ian.ray@gehealthcare.com>
 S:	Maintained
 F:	arch/arm/dts/imx8mp-msc-sm2s*
 F:	board/msc/sm2s_imx8mp/